Tow crimping apparatus



United States Patent ()fitice 3,076,250 Patented Feb. 5, 1963 3,076,250 TOW CRIMPING APPARATUS Russel F. Baer, Decatur, Ala., assignor, by mesne assignments, to Monsanto Chemical Company, a corporation of Delaware Filed Dec. 5, 1960, Ser. No. 73,895 6 Claims. (Cl. 28-1) This invention relates to tow crimping apparatus and more particularly to apparatus for crimping a tow of thermoplastic filaments.

In currently used tow crimpers, filament damage is often caused by doctor blades and other parts which become out of adjustment. Also, wear on the various parts of the crimping device necessitates frequent adjustment. With this in mind, one of the objects of this invention is to provide a tow crimping apparatus which is self-adjusting.

Another object of this invention is to provide a novel and improved tow crimping apparatus.

A further object of this invention is to provide a tow crimping apparatus having a plurality of spring-loaded vanes carried by a rotor and which engage and crimp the tow.

Still another object of this invention is to provide a tow crimper wherein a tow-containing space is decreased in volume to crimp the tow.

One embodiment of this invention contemplates a tow crimping apparatus having a cylindrical housing having a first opening for receiving a tow and a second opening for discharging the tow, a pair of feed rolls advancing the tow into the housing. A rotor mounted in the housing at a position eccentric or off center to the housing carries a plurality of spring-loaded vanes which engage the tow and carry it around the periphery of the housing to the discharge opening. A clapper bar mounted in the discharge opening serves to resist the passage of the tow to further aid in the crimping operation.

Other objects and advantages of the invention will become apparent when the following detailed description is read in conjunction with the appended drawing, in which:

FIGURE 1 is a plan view of an apparatus illustrating the principles of the invention and showing the general arrangement of the apparatus;

FIGURE 2 is a front view of the disclosure of FIG- URE 1; and

FIGURE 3 is an enlarged sectional view taken along line 3-3 of FIGURE 2 showing the construction of a rotor which moves the tow through the housing.

Referring now in detail to the drawing, a base 11 is shown supporting a cylindrical housing 12 having a first opening 13 for receiving a heated and moistened tow 14 and a second opening 15 for discharging the tow. The tow 14 is advanced through the opening 13 into the housing by a pair of cooperating rolls 16 rotatably mounted on a bracket 17 secured to the housing 12 and which are driven in a well known manner. A rotor 18 having a plurality of spaced radial slots 19 is carried by a shaft 20 which is rotatably mounted in brackets 21 and 22. The brackets 21 and 22 are adjustably secured to the housing 12 and to the base 11 so that the position of the rotor 18 may be varied relative to the housing 12. A motor 23 turns the shaft 20 to drive the rotor 18.

A plurality of vanes 27 slidably mounted in the slots 19 are urged outward into engagement with the inner surface of the housing 12 by compression springs 28 mounted in the slots 19. The ends of the vanes 27 engage the tow 14 at spaced intervals and hold the tow against the inner surface of the housing 12 as the rotor 18 is driven. It can be seen that adjacent vanes. define a volume, the cross-sectional width of which is limited by the rotor 18 and the housing 12. Because of the eccentric positioning of the rotor 18 this volume varies as the rotor 18 is turned. The feed rolls 16 are positioned at the side of the housing where the rotor 18 and the housing 12 are furthest apart, the voluume defined by adjacent vanes 27, the housing and the rotor being near maximum at this location.

The feed rolls 16 advance the tow 14 into the abovedescribed volume at a rate of speed sutficient to substantially fill this volume. As the tow is moved by the vanes 27 toward the discharge opening 15, the volume defined by the adjacent vanes, the rotor and the housing is decreased to compress the tow. Since the tow is heated and moistened (in a well known manner) prior to entry into the housing, this compressing action serves to fully crimp the tow.

A clapper bar 30 pivotally mounted on the housing 12 in the discharge opening 15 serves to restrict the discharge of the crimped tow through the opening 15. The piston of an air cylinder 31 is connected by a rod 32 to the clapper bar 30 for urging the clapper bar against the tow to resist the passage thereof.

At the trailing side of the discharge opening 15 the rotor 18 is very close to the housing 12. This causes the above-described volume to be so small at this location that the tow displaces the clapper bar 30 against the action of the cylinder 31 and passes through the discharge opening 15. The housing 12 at the trailing side of the opening 15 is provided with a doctor blade 33 which insures that the crimped tow exits through the opening 15.

In operation of the apparatus, the motor 23 drives the rotor 18 in a counterclockwise (FIG. 3) direction. The tow 14, fed by the rolls 16, fills the spaces between the moving vanes 27 at the opening 13and is carried around the periphery of the housing 12. As the vanes 27 move from the opening 13 toward the discharge opening 15, the space between the housing and the rotor decreases to crimp the tow held therein. By adjustment of the position of the shaft 20, the eccentricity of the motor 18 relative to the housing 12 may be adjusted to vary the amount of crimp applied to the tow 14.

It is to be understood that the embodiment disclosed herein may be modified or altered and that numerous other embodiments may be contemplated without departing from the spirit and scope of the invention;

What is claimed is:

1. An apparatus for crimping a tow, comprising a frame, a generally cylindrical housing mounted on the frame and having a first opening for receiving a tow, a rotor mounted in the housing at a position eccentric to said housing, a plurality of radially extending vanes slidably mounted on the rotor at spaced intervals, means urging the vanes outward from the rotor, said housing having a second opening for discharging the tow, a clapper bar movably mounted in the second opening for resisting the passage of the tow, and means for urging the clapper in a direction to close said second opening. I

2. An apparatus for crimping a tow, comprising a frame, a substantially cylindrical housing mounted on the frame and having a first opening for receiving a tow to be crimped, a rotor mounted in the housing at a position eccentric to said housing and having therein a plurality of spaced radial slots, a plurality of vanes slidably mounted in the slots, means for urging the vanes radially outward into engagement with the housing, said housing having .a second opening for discharging the tow, a clapper bar pivotally mounted on the housing and positioned in said second opening for resisting said discharge, means for urging the clapper bar in a direction to close said second opening, and means for driving the rotor.

3. An apparatus for crimping a tow, comprising a frame, a substantially cylindrical housing mounted on the frame and having a first opening on one side thereof for receiving a tow, a rotor mounted in the housing eccentric to said housing and having a plurality of spaced radial slots, a plurality of vanes slidably mounted in said slots, a plurality of springs mounted in the slots for urging the vanes radially outward into engagement with the housing for holding the tow against the housing, said housing having a second opening opposite said first opening for discharging the tow, a clapper bar pivotally mounted on the housing and in said second opening, and a fluid cylinder having a piston connected to the clapper bar for urging said clapper bar against the tow.

4. An apparatus for crimping a tow, comprising a frame, a cylindrical housing mounted on the frame and having a first opening on one side thereof for receiving a tow, a rotor mounted in the housing eccentric thereto and having therein a plurality of spaced radial slots, a plurality of vanes slidably mounted in the slots in the rotor, means in the slots for urging the vanes radially outward into engagement with the housing, said housing having a second opening opposite the first opening for discharging the tow from said housing, and means positioned in the second opening for resisting said discharge of the tow.

5. An apparatus for crimping a tow, comprising a frame, a cylindrical housing mounted on the frame and having therein a first opening for receiving a tow, a pair of feed rolls mounted on the housing adjacent to the first opening for advancing the tow into the housing through said opening, a rotor mounted in the housing at a position eccentric to said housing and having therein a plurality of spaced radial slots, a plurality of vanes slidably mounted in the slots, means for urging the vanes radially outward into engagement with the housing, said housing having a second opening for discharging the tow therefrom, said rotor being positioned in close promixity to the housing at said second opening, and a clapper bar mounted in the second opening for resisting the discharge of the tow, said housing having a doctor blade at the trailing side of the second opening for preventing further passage of the tow in the housing.

6. An apparatus for crimping a tow, comprising a frame, a cylindrical housing mounted on the frame and having therein a first opening for receiving a tow, a pair of feed rolls mounted on the housing adjacent to the first opening for advancing the tow into the housing through said opening, a rotor adjustably mounted in the housing at a position eccentric to said housing and having therein a plurality of spaced radial slots, said rotor being adjustably mounted in the housing to vary the eccentricity of said rotor relative to said housing, a plurality of vanes slidably mounted in the slots, means for urging the vanes radially outward into engagement with the housing, said housing having a second opening for discharging the tow therefrom, said rotor being positioned in close proximity to the housing at said second opening, and a clapper bar mounted in the second opening for resisting the discharge of the tow, said housing having a doctor blade at the trailing side of the second opening for preventing further passage of the tow in the housing.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN APPARATUS FOR CRIMPING A TOW, COMPRISING A FRAME, A GENERALLY CYLINDRICAL HOUSING MOUNTED ON THE FRAME AND HAVING A FIRST OPENING FOR RECEIVING A TOW, A ROTOR MOUNTED IN THE HOUSING AT A POSITION ECCENTRIC TO SAID HOUSING, A PLURALITY OF RADIALLY EXTENDING VANES SLIDABLY MOUNTED ON THE ROTOR AT SPACED INTERVALS, MEANS URGING THE VANES OUTWARD FROM THE ROTOR, SAID HOUSING HAVING A SECOND OPENING FOR DISCHARGING THE TOW, A CLAPPER BAR MOVABLY MOUNTED IN THE SECOND OPENING FOR RESISTING THE PASSAGE OF THE TOW, AND MEANS FOR URGING THE CLAPPER IN A DIRECTION TO CLOSE SAID SECOND OPENING. 